As light emitting diode (LED) has advantages such as long life, low energy consumption, and quick start, LED devices have been widely used in fields such as signal lights, automobile lights, large screen display and illumination. At present, the most commonly used white LED achieves white light by combining blue LED chips with fluorescent powders. The mechanism thereof is: blue light chips stimulate the fluorescent powders to emit yellow light, and blue light and yellow light complement with each other to produce a visible white light. The fluorescent powders currently used for white LED are mainly cerium-doped yttrium aluminum garnet (YAG:Ce) fluorescent powder, silicate fluorescent powder, nitride fluorescent powder, and the like, among which the YAG:Ce fluorescent powder is the most widely used. However, it is difficult to control the shape and particle size of the fluorescent powder, which leads to a high cost for manufacturing high-quality fluorescent powder for white LED. In addition, during the encapsulating process, fluorescent powder should be mixed with glue. In the mixture of fluorescent powder with glue, due to the poor compatibility of the two components, fluorescent powder tends to precipitate, resulting in non-uniform distribution of the glue, which in turn results in poor uniformity of the light emission of the LED device, and poor color tone consistency. This leads to a high cost of light separation for white LED. Due to the high cost and inconsistent property, the white LED materials used in many encapsulating factories in China still rely on importation.